The following example policy will find any VPC Flow Log in your region that is
not properly configured and notify a group via email. Ensuring VPC Flow Logs
are enabled and setup properly is very important for compliance and security.
Flow Logs themselves capture IP traffic information to and from network
interfaces and can be used for troubleshooting traffic issues and montitoring
network traffic as a security tool. See more info on example dashboarding
of VPC Flow Logs using Elasticsearch and Kibana
https://aws.amazon.com/blogs/aws/cloudwatch-logs-subscription-consumer-elasticsearch-kibana-dashboards/